A new study, published Sept. 25 in Cancer Discovery, reveals key insights into the biological factors shaping efficacy of off-the-shelf CAR-T cell therapies. Andrew Jallouk, MD, PhD, Assistant Professor of Medicine in the Division of Hematology/Oncology, was lead author of the study.
Currently, standard CAR-T therapies require a patient’s own T cells to be collected, genetically engineered and returned to the patient —a complex process which can take several weeks. Off-the-shelf CAR-T therapies are prepared in advance and immediately available when needed, making them easier for patients to access. However, the response to these therapies may vary due to characteristics of the individual patient or product.
Jallouk explained, “As part of this work, we identified both patient and product features which contribute to CAR-T efficacy. These findings help explain why patients can have very different responses to the exact same off-the-shelf CAR-T therapy.”
The team’s findings could lead to new strategies which improve efficacy of these treatments and expand life-saving options for cancer patients.
Balance between immune rejection and CAR-T expansion
The researchers evaluated patients with relapsed or refractory large B-cell lymphoma who received cemacabtagene ansegedleucel (cema-cel, Allogene Therapeutics), an investigational off-the-shelf CAR-T cell product. Using advanced molecular and immune profiling, the team tracked how the engineered immune cells behaved post-infusion and monitored how patients’ immune systems reacted to them.
The study found that pre-existing immune defenses in a subset of patients targeted and rejected the CAR-T cells. This process limited the therapy’s effectiveness in these patients. In contrast, patients whose CAR-T cells expanded successfully showed little evidence of immune rejection. Additionally, the study found that certain CAR T cell populations consistently demonstrated a greater ability to expand across multiple patients and disease settings.
Building better off-the-shelf CAR-T therapies
These results establish a framework for enhancing next-generation CAR-T cell therapies by helping manufacturers further optimize donor selection and production methods. They also help physicians identify patients who may respond best to CAR T therapies prior to treatment.
Jallouk summarized, “Our findings provide a roadmap for improving future allogeneic CAR-T cell therapies. By identifying patients who may be more likely to reject off-the-shelf CAR-T cells and refining how these therapies are developed, we can work toward more effective and personalized treatments.”
The study was supported by funding from Allogene Therapeutics, the University of Texas MD Anderson Cancer Center, Conquer Cancer, the Lymphoma Research Foundation, the Cancer Prevention and Research Institute of Texas and the National Cancer Institute (1K08CA248458-01). A full list of collaborating authors and their disclosures may be found with the full paper in Cancer Discovery.
